Question: William ate 1 slice of pie. Umaima ate 3 slices. If William ate $\dfrac{1}{9}$ of the pie, what fraction of the pie is remaining?
Explanation: If 1 slice represents $\dfrac{1}{9}$ of the pie, there must have been a total of 9 slices. $\text{fraction of pie remaining} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 4 slices, which leaves 5 out of 9 slices remaining. There is $\dfrac{5}{9}$ of the pie remaining.